From a599974a9b7fc92d68011dafc969e83e469a6472 Mon Sep 17 00:00:00 2001
From: Martin Plicht <mardmol@gmx.de>
Date: Sun, 3 Nov 2013 01:41:16 +0100
Subject: [PATCH] mac: Use OSX Mavericks occlusionState API to test whether
 window is visible and needs drawing or not (should still work on Mountain
 Lion due to runtime check for API availability)

---
 src/graphics/C4DrawGLMac.mm | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/graphics/C4DrawGLMac.mm b/src/graphics/C4DrawGLMac.mm
index f29191dc4..cae0b1e82 100644
--- a/src/graphics/C4DrawGLMac.mm
+++ b/src/graphics/C4DrawGLMac.mm
@@ -115,12 +115,22 @@
 	// better not to draw anything when the game has already finished
 	if (Application.fQuitMsgReceived)
 		return;
+
 	// don't draw if tab-switched away from fullscreen
-	if ([self.controller isFullScreenConsideringLionFullScreen] && ![NSApp isActive])
-		return;
-	if ([self.window isMiniaturized] || ![self.window isVisible])
-		return;
-	//[self.context update];
+	if ([NSApp respondsToSelector:@selector(occlusionState)])
+	{
+		// Mavericks - query app occlusion state
+		if (([NSApp occlusionState] & NSApplicationOcclusionStateVisible) == 0)
+			return;
+	}
+	else
+	{
+		if ([self.controller isFullScreenConsideringLionFullScreen] && ![NSApp isActive])
+			return;
+		if ([self.window isMiniaturized] || ![self.window isVisible])
+			return;
+	}
+
 	C4Window* stdWindow = self.controller.stdWindow;
 	
 	if (stdWindow)